Three-week-old chicks were inoculated via the foot pad with the avian reovirus (strain WVU 2937) that has been proved to be the causative agent in avian viral arthritis. The initial stages of the avian reovirus infection in the synovium of the hock joint were studied by transmission electron microscopy to shed light on the early virus-host relationship of an arthrotropic virus and synovial tissue. At 48 hours postinoculation (PI), coated, partially coated, and uncoated virus particles were seen in a dense lysosome-like inclusion in the cytoplasm of subsynovial fibroblasts. Virus replication was demonstrated in fibroblasts of the subsynovium 4 days PI. Infiltration of leukocytes into the area of the virus replication was noted at the time of virus replication (4 days PI). By the second week of the infection (11 days PI), the subsynovium was heavily infiltrated with lymphocytes and plasma cells, and proliferative changes had occurred in the synovial lining cells.

Animals↗

PubMedDate not supplied

Variability of human coronary artery geometry: an angiographic study of the left anterior descending arteries of 30 autopsy hearts.

A computer-based system is described to measure objectively the geometric parameters of arteries from pairs of projection angiograms. This technique, which employs back-projection to define the vessel axes in 3-D space, was used to obtain selected parameters of coronary artery geometry from radiographic images of autopsy hearts. Results of the first 30 cases are presented, focussing on the distribution of the geometric parameters of the left anterior descending coronary artery (LAD) and its first two major branches. The derived parameters include the angle between the left circumflex artery and the LAD; the angles between the LAD and its early diagonal and septal perforator branches; distances between branch points; and tortuosity. The geometric parameters vary considerably, presumably contributing to a corresponding variability in local hemodynamic and mechanical stresses. Most parameters are uncorrelated. One exception is the angle at the origin of the second diagonal branch, which is positively correlated (p < 0.01) with the distance between the ostia of the first two diagonal vessels; this correlation could reflect the existence of "target" perfusion regions. No relation between geometric parameters and age or gender was seen. In this sample, blacks had a larger angle at the left main bifurcation than whites (p < 0.05).

Autopsy↗

PubMedDate not supplied

Measurement of the geometric parameters of the aortic bifurcation from magnetic resonance images.

This paper presents a method for measuring arterial geometry in vivo using MRI. The approach was validated using MR images of three perfused compliant casts of human aortic bifurcations whose geometry was known. Preliminary human studies demonstrated the reproducibility of the technique. The approach was applied to 20 normal individuals to study the effects of age, race, and gender on the geometry of the aortic bifurcation. The results show that older people tend to have a smaller bifurcation angle, lower planarity, and larger angular asymmetry than younger people. Asians have larger bifurcation angles than whites. The bifurcation of males is more asymmetric than that of females. These results may have implications regarding the heritability of arterial geometry, the similarities of cardiovascular risk within families, and differences in risk among groups.

Age Factors↗

PubMedDate not supplied

Intraoral chilling versus oral sumatriptan for acute migraine.

Migraine pathophysiology is associated with a dural inflammation. Recent evidence suggests that the primary inflammation occurs in a maxillary nerve segment, accessible intraorally. Local tenderness, related to symptom laterality, has been palpated consistently in asymptomatic migraine patients, and significant migraine relief has been obtained from chilling confined to this area. Thirty-five symptomatic episodic migraine patients were enrolled in this study, comparing 40 minutes of bilateral intraoral chilling, 50 mg of oral sumatriptan, and 40 minutes of sham (tongue) chilling. Hollow metal tubes chilled by circulating ice water were held in the maxillary molar periapical areas by the patient. Pain and nausea were recorded at baseline and 1, 2, 4, and 24 hours after start of treatment, using a numeric symptom-relief scale. Significant mean headache relief was obtained by maxillary chilling and sumatriptan at all four time intervals, with poor relief obtained by placebo. Maxillary chilling was more effective than sumatriptan at all four time intervals. Significant nausea relief was obtained by maxillary chilling and sumatriptan at posttreatment and 2 and 4 hours later. At 24 hours, some headache and nausea recurrence was noted with sumatriptan. The repeated-measures analysis of variance indicated that both treatments, drug (P = 0.024) and maxillary chilling (P = 0.001), reduced the headache, as compared with the control group. Tenderness suggests local inflammation associated with vasodilatation and edema. Because chilling can resolve local edema, these findings raise the possibility that an intraoral inflammation may be a factor in migraine etiology.

Administration, Oral↗

PubMedDate not supplied

Method for assessing the need for case-specific hemodynamics: application to the distribution of vascular permeability.

A common approach to understanding the role of hemodynamics in atherogenesis is to seek relationships between parameters of the hemodynamic environment, and the distribution of tissue variables thought to be indicative of early disease. An important question arising in such investigations is whether the distributions of tissue variables are sufficiently similar among cases to permit them to be described by an ensemble average distribution. If they are, the hemodynamic environment needs be determined only once, for a nominal representative geometry; if not, the hemodynamic environment must be obtained for each case. A method for classifying distributions from multiple cases to answer this question is proposed and applied to the distributions of the uptake of Evans blue dye labeled albumin by the external iliac arteries of swine in response to a step increase in flow. It is found that the uptake patterns in the proximal segment of the arteries, between the aortic trifurcation and the ostium of the circumflex iliac artery, show considerable case-to-case variability. In the distal segment, extending to the deep femoral ostium, many cases show very little spatial variation, and the patterns in those that do are similar among the cases. Thus the response of the distal segment may be understood with fewer simulations, but the proximal segment has more information to offer.

Animals↗

PubMedDate not supplied

Distribution of the geometric parameters of human aortic bifurcations.

The distribution of flow divider offset, branch angle, and angular asymmetry in a collection of 70 human aortic bifurcations are reported. A computer algorithm was used to determine these parameters objectively. The mean values with standard deviations and ranges are: 1) magnitude of flow divider offset = 1.4 +/- 1.4 mm (range = 0.04 to 8.1 mm); 2) branch angle = 35.0 degrees +/- 11.1 degrees (range = 10.4 degrees to 61.3 degrees); and 3) angular asymmetry = 15.3 degrees +/- 12.9 degrees (range 0.2 degrees to 56.1 degrees). Since these parameters have been shown to have a significant influence on hemodynamic shear, their variability suggests a corresponding variability in the fluid dynamic stresses to which the bifurcations were exposed in life.

Adult↗

PubMedDate not supplied

A biologically plausible model of thickening of arterial intima under shear.

A biologically plausible model of the early thickening of the arterial intima has been developed to interpret experimental data relating hemodynamic shear to human intimal morphology. The model included many processes known or commonly believed to take place in the vascular intima, including: smooth muscle cell migration, proliferation, metabolism, and expression of extracellular matrix; lipoprotein kinetics and binding; and monocyte chemotaxis, conversion to macrophage, and foam cell formation. Certain of these processes were allowed to be shear-dependent. The best fit to the data was obtained when smooth muscle cell accumulation was more rapid, and extracellular matrix expression proceeded more slowly where the fluid shear was relatively high and unidirectional. This result is consistent with the earlier inference that competing shear-dependent processes take place in the wall; it is also consistent with the notion that intimal thickening might be part of an adaptive mechanism by which the artery maintains a favorable shear environment.

Arteries↗

PubMedDate not supplied

Condylar displacement recordings as an analog of mandibular movements.

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Dental Occlusion, Centric↗

PubMedDate not supplied

Role of afferent sensors in the initiation of swallowing in man.

Chewing and swallowing sounds that were recorded on magnetic tape by means of a paralaryngeally placed contact microphone were used to evaluate temporal relationships of the events of the swallowing cycle in young women. Temporal inter-event parameters indicate a reflex nature for the initiation of swallowing, and the effects of topical anesthesia suggest a triggering mechanism for swallowing similar to the gating theory for pain proposed by Melzack and Wall.

Administration, Topical↗

PubMedDate not supplied

Acoustic profile of deglutition.

Explore the source record for details and available documents.

Adult↗

PubMedDate not supplied

The hypomobile temporomandibular joint.

The hypomobile (restricted) temporomandibular joint (TMJ) is usually caused by a restricted joint capsule or by an anteriorly displaced disk. Here, painful unilateral hypomobility (19 mm jaw opening), with normal disk position, caused by voluntary immobilization after a dental procedure, was the presenting symptom. Management included inflammation control, TMJ manipulation (mobilization), and lateral pterygoid muscle relaxation. Inflammation and pain were alleviated by nonsteroidal anti-inflammatory drugs (NSAIDs) and local TMJ ice massage. TMJ mobilization was performed at every visit, to tear joint capsule adhesions and to realign collagen fibers. Exercise consisted mainly of resistive opening (the patient resists an upward force applied to the chin), with the jaw maintained at full opening. This produced lateral pterygoid muscle relaxation at full length, aiding in the restoration of a pain-free 44 mm opening.

Aged↗